In order to authenticate multiple devices and encrypt communication paths, certificates and private keys prepared in advance are distributed to respective devices via a network. In this Specification, the “device” refers to an intelligent node having an OS (Operating System) among those constituting a network, and the examples of the device include network devices such as a switch and a router, and information processing devices such as a computer and a server.
As distribution of the certificate and the private key, it is typical a user uses and brings in a medium and directly installs the same into a device rather than via a network, which is the most secure method. Because this method causes too much trouble when a large number of devices are involved to be distributed, other methods for distributing certificates and private keys have been proposed. For example, in the method described in Patent Literature 1, a server for certificate distribution is provided, and a user terminal and a distribution destination device are locally connected to each other where a connection via a network is not established, thereby isolating the distribution destination device from the network, and improving security.